Inert gas producing apparatus



1946. w. J. WILLE NBORG 2,392,711

INER'IQGAS PRODUCING APPARATUS I Filed April 12, 1944' I N VEN TOR. Ill917i? (17% s/vaam Patented Jan. 8, 1946 UNITED STATES I PATENT OFFICE Immr cAsraif t izi so APPARATUS 4 Q to Inert Gas Equipment, Inc., NewYork, N.

a corporation. of New York Application April 12, 1944, Serial No.530,721

8 Claims.

This invention relates particularly to an improved method and apparatusfor the production of inert gas, although it may be used for otherpurposes where applicable.

The exhaust gases from an internal combustion engine are used as asource of the inert gas. After the exhaust gases are treated forremoving impurities and compressed they are delivered under pressure ofseveral hundred pounds to a storage tank and used in various ways forprotective purposes. The inert gas consists mainly of nitrogen and alesser percentage of carbon dioxide.

The main object of the invention is to provide an apparatus and methodof control which will operate at high efliciency in producing a maximumof inert gas from the available capacity of the apparatus. Anotherobject is to accomplish this by apparatus of a simple character whichmay be easily controlled and adjusted for obtaining the best results.Another object is to avoid the cost and use of regulating valves whichrequire special care and maintenance. A further object is to providecontrolling means which will occupy a small amount of space and bedependable and durable under long continued use. Other objects andadvantages will be understood from the following description andaccompanying drawing. I

The drawing is a diagram of the various parts and theirinterrelationship showing one embodiment of the invention.

In general the invention is based upon the'use of a multi-stagecompressor driven by the internal combustion engine and the introductionbetween stages of an adjustable control of a simple character, such asby a needle valve, for the purpose of imposing a proper load and backpressure upon the driving engine and for properly proportioning thecompression of the gases in the different compression stages.

The production and storage of inert gases requires the use of acompressor together with coolers, scrubbers, filters and the like forproper treatment of the exhaust gases from the engine. By causing thegas engine to drive the compressor, a load is imposed on the engine forthe production of the exhaust gases. However, this is not suflicient,when using a standard compressor, to cause the engine to use up enoughfuel to produce the desired quantity and in some cases quality ofexhaust gases. Prior to this invention this difliculty was overcome byrecirculating part of the compressed gases to the intake of thecompressor. This, of course, increased the load on the engine andincreased the amount of exhaust and filtering of gases which had beengases. But such recirculation has the disadvantage of requiring therecompressing, scrubbing previously so treated.

By the present invention, this recirculating is avoided which permitsthe size of the scrubbers and filters to be much smaller than heretoforerequired for the same output of inert gas. This is accomplished byraising the inter-stage pressure of'a multi-stage compressor. Thisincreases the load on the compressor which in turn increases the load onthe engine and increases the production of the exhaust gases. Althoughthe efliciency and capacity of the compressor is reduced by the increaseof the inter-stage pressure, the over-all production of the inert gasproduct by the apparatus is greatly increased by this improvement.

Referring to the drawing, the internal combustion engine I, usually ofthe gasoline type, is shown directly driving a two-stage compressorhaving the first stage 2 and a second stage 3. The out1et'4 from theengine exhaust is connected to a scrubber 6 which is provided with apressure gauge 5. The exhaust gases are I washed and cooled in thescrubber. The outlet 1 for the gases is connected to a suitable filter 8from which connection is made by the pipe 9 to the intake of the firststage of the compressor. is provided with a relief valve 13a.

The outlet of the first compression stage is connected by the pipe in toan inter-cooler ii, the pipe in being provided with a pressure gauge l2and a safety valve i3 The outlet from the intercooler is passed throughan adjustable valve II which is capable of refined adjustment, such as aneedle valve, as shown. The outlet from this valve is connected by thepipe I5 to the inletof the second stage 3 of the compressor. Theconnection between the needle valve and the second compression stage isprovided with a pressure gauge [6 and a pulsating chamber IT. The needlevalve is in itself may be insufiicient to pass the full volume of thegases and a by-pass I8 is connected around it for passing the largervolume of the gases. This by-pass is shown provided with a union is forforming a restricted orifice for controlling the volume of the gasespassed through it. This restricted orifice is shown in the form of aperforated disk or washer 20 positioned between the meeting faces of theunion. In order to properly relate the volume of gases passed throughthis restricted orifice with reference to that controlled by theadjustable valve ll, the disk 20 may readily be replaced by one having alarger or smaller perforation; and after the proper sized The connection9 orifice is once determined, it may remain fixed, the refinement ofcontrol being accomplished by the needle valve ll.

The outlet from the second stage of the compressor is connected by apipe 2| to another scrubber 22, the outlet from which is connected toanother filter 23 and thence through the load valve 24 to a storage tankor other devices where the inert gas is to be used for protectivepurposes.

The refinement of control is accomplished by the adjustable needle valvel4 and may be set to impose any desired outlet pressure upon the firststage of the compressor within required limits and this pressure is madesuflicient to impose a greater load on the engine, thereby forcing it todo more work, to burn more fuel, and thus create more inertgases and aconsequent greater amount for the compressor to take away, therebyimposing a back pressure upon the exhaust 01' the combustion enginewhich pressure should be maintained at least above atmospheric pressure.Thus the adjustment of the needle valve not only determines the pressureunder which the diiierent stages are caused to work and therebydetermines the engine and compressor loads but also imposes a desirablepressure above atmosphere on the engine exhaust. The load may be madethe full horse power which the engine is capable of delivering andthereby a maximum amount of inert gases are obtained from the engineexhaust.

An adjustable clearance pocket may also be provided for either or bothof the compression stages of the compressor for additional control ofthe compressor output. In the drawing a clearancepocket 25 is shown insection in the head of the second stage of the compressor. An axiallyadjustable rod 26 projects within the ocket and extends outwardlythrough a stuiiing. box 21. The rod has a threaded engagement with theinterior of the stuffing box'for adjusting the distance the rod extendswithin the pocket. The

rod is held in any fixed position by lock nuts on opposite sides of afixed support 28 which loosely embraces the rod. The more the rod isadjusted inwardly to reduce the size of the clearance pocket, thegreater will be the efficiency of the compressor and the more the rod isadjusted outwardly, the less the efficiency of the compressor.

In this manner the compressor efiiciency can beadjusted so that the gashandled by the compressor is in balance or partiall in balance with theoutput of the gas from the engine. An adjustable clearance pocket deviceis indicated in the drawing on the first compression stage as well ,ason the second stage. These devices may be used instead of the adjustableneedle valve already described or in addition thereto for obtainingadditional-control.

It will be appreciated that the required control apparatus for obtainingthe maximum output of inert gas within the capacity of the engine andcompressor is of a simple character and occupies small space. It iscapable 01' being readily adjusted and of being maintained adjusted forthe best results with a proper load on the engine and properproportioning of the work on the two stages of the compressor. It avoidsthe cost, complication and repair of regulating valves. It likewiseavoids the necessity i'or any by-passing of the inert gas from a highpressure source to the inlet of the compressor for obtaining a desirablepositive pressure thereon; and by eliminating this recirculation of aportion of the inert gas, the efflciency and output of the apparatus iscorrespondingly increased,

Although a'particular embodiment of the invention has been described, itwill be understood that it is capable of various modifications forparticular requirements; and more than two compression stages may beutilized when desirable.

I claim:

l. Gas producing apparatus comprising an internal combustion engine, amulti-stage compressor driven thereby, connections from the exhaust ofthe engine to the intake of the first stage of the compressor,connections between successive stages of the compressor and to the inertgas load, and an adjustable valve in a connection between stages foradjusting the back pressure of a prior stage.

2. Gas producing apparatus comprising an internal combustion engine, amulti-stage compressor driven thereby, connections from the exhaust ofthe engine to the intake of the first stage of the compressor,connections between successive stages of the compressor and to the inertgas load, an adjustable valve in a connection between stages foradjusting the back pressure of a prior stage, and a restricted by-passaround said valve.

3. Gas producing apparatus comprising an internal combustion engine, amulti-stage compressor driven thereby, connections from the exhaust ofthe engine to the intake of the first stage of the compressor,connections between successive stages of the compressor and to the inertgas load, and an adjustable needle valve in a connection between stagesfor adjusting the back pressure of a prior stage.

4. Gas producing apparatus comprising an internal combustion engine, amulti-stage compressor driven thereby, connections from the exhaust ofthe engine to the intake of the first stage of the compressor,connections between suc cessive stages of the com-pressor and to theinert gas load, an adjustable needle valve in a con first stage of thecompressor to the inlet of the second stage and from the outlet of thesecond stage to the inert gas load, and an adjustable valve in theconnection between the first stage and the second stage for adjustingthe back pressure-of the first stage.

6. Gas producing apparatus comprising an internal combustion engine, a.multi-stage ,compressor driven thereby, connections from the exhaust ofthe engine to the first stage of the compressor, connections between theoutlet of the first stage of the compressor to the inlet of the secondstage and from the outlet of the second stage to the inert gas load, anadjustable valve in the connection between the first-stage and thesecond stage for adjusting the back pressure gas load, and a variableclearance pocket device on at least one 01' the stages of thecompressor.

8. Gas producing apparatus comprising an .in-

ternal combustion engine, a multi-stage compresso'z' driven thereby,connections from the exhaus of the engine to th intake of the firststage of the compressor, connections between successive stages of thecompressor and to the inert gas load, an adjustable valve in aconnection between stages for adjusting the back pressure of a priorstage, and a variable clearance pocket device on at least one of thestages of the compressor.

WALTER J WILIENBORG.

